对于KivyMD MDBottomNavigationItem，是否可以更改文本，使其不是全部大写？

from kivymd.app import MDApp
from kivymd.uix.bottomnavigation import MDBottomNavigation, MDBottomNavigationItem
from kivymd.uix.label import MDLabel

class TestApp(MDApp):
    def build(self):
        bottom_navigation = MDBottomNavigation()
        
        # 创建一个MDBottomNavigationItem并更改文本
        item1 = MDBottomNavigationItem(text='Item 1')
        item1.ids._label.text_transform = 'none'  # 设置文本不转换为大写
        bottom_navigation.add_widget(item1)
        
        # 创建另一个MDBottomNavigationItem并直接设置文本
        item2 = MDBottomNavigationItem()
        item2.add_widget(MDLabel(text='Item 2', halign='center'))
        bottom_navigation.add_widget(item2)
        
        return bottom_navigation

TestApp().run()